/*******************************************************************************
 * Copyright (c) 2012 joey.enfield.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/gpl.html
 * 
 * Contributors:
 *     joey.enfield - initial API and implementation
 ******************************************************************************/
package com.joey.software.VolumeToolkit;

/*
 *	@(#)ExtensionFileFilter.java 1.3 99/09/15 13:44:11
 *
 * Copyright (c) 1996-1999 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

import java.io.File;
import java.util.Enumeration;
import java.util.Hashtable;

import javax.swing.filechooser.FileFilter;

/**
 * A convenience implementation of FileFilter that filters out all files except
 * for those type extensions that it knows about.
 * 
 * Extensions are of the type ".foo", which is typically found on Windows and
 * Unix boxes, but not on Macinthosh. Case is ignored.
 * 
 * Example - create a new filter that filerts out all files but gif and jpg
 * image files:
 * 
 * JFileChooser chooser = new JFileChooser(); ExtensionFileFilter filter = new
 * ExtensionFileFilter( new String{"gif", "jpg"}, "JPEG & GIF Images")
 * chooser.addChoosableFileFilter(filter); chooser.showOpenDialog(this);
 * 
 * @version 1.8 08/26/98
 * @author Jeff Dinkins
 */
// renamed from ExtensionFileFilter to ExtensionFileFilter
public class ExtensionFileFilter extends FileFilter
{

	private static String TYPE_UNKNOWN = "Type Unknown";

	private static String HIDDEN_FILE = "Hidden File";

	private Hashtable filters = null;

	private String description = null;

	private String fullDescription = null;

	private boolean useExtensionsInDescription = true;

	/**
	 * Creates a file filter. If no filters are added, then all files are
	 * accepted.
	 * 
	 * @see #addExtension
	 */
	public ExtensionFileFilter()
	{
		this.filters = new Hashtable();
	}

	/**
	 * Creates a file filter that accepts files with the given extension.
	 * Example: new ExtensionFileFilter("jpg");
	 * 
	 * @see #addExtension
	 */
	public ExtensionFileFilter(String extension)
	{
		this(extension, null);
	}

	/**
	 * Creates a file filter that accepts the given file type. Example: new
	 * ExtensionFileFilter("jpg", "JPEG Image Images");
	 * 
	 * Note that the "." before the extension is not needed. If provided, it
	 * will be ignored.
	 * 
	 * @see #addExtension
	 */
	public ExtensionFileFilter(String extension, String description)
	{
		this();
		if (extension != null)
			addExtension(extension);
		if (description != null)
			setDescription(description);
	}

	/**
	 * Creates a file filter from the given string array. Example: new
	 * ExtensionFileFilter(String {"gif", "jpg"});
	 * 
	 * Note that the "." before the extension is not needed adn will be ignored.
	 * 
	 * @see #addExtension
	 */
	public ExtensionFileFilter(String[] filters)
	{
		this(filters, null);
	}

	/**
	 * Creates a file filter from the given string array and description.
	 * Example: new ExtensionFileFilter(String {"gif", "jpg"}, "Gif and JPG
	 * Images");
	 * 
	 * Note that the "." before the extension is not needed and will be ignored.
	 * 
	 * @see #addExtension
	 */
	public ExtensionFileFilter(String[] filters, String description)
	{
		this();
		for (int i = 0; i < filters.length; i++)
		{
			// add filters one by one
			addExtension(filters[i]);
		}
		if (description != null)
			setDescription(description);
	}

	/**
	 * Return true if this file should be shown in the directory pane, false if
	 * it shouldn't.
	 * 
	 * Files that begin with "." are ignored.
	 * 
	 * @see #getExtension
	 * @see FileFilter#accepts
	 */
	@Override
	public boolean accept(File f)
	{
		if (f != null)
		{
			if (f.isDirectory())
			{
				return true;
			}
			String extension = getExtension(f);
			if (extension != null && filters.get(getExtension(f)) != null)
			{
				return true;
			}
			;
		}
		return false;
	}

	/**
	 * Return the extension portion of the file's name .
	 * 
	 * @see #getExtension
	 * @see FileFilter#accept
	 */
	public String getExtension(File f)
	{
		if (f != null)
		{
			String filename = f.getName();
			int i = filename.lastIndexOf('.');
			if (i > 0 && i < filename.length() - 1)
			{
				return filename.substring(i + 1).toLowerCase();
			}
			;
		}
		return null;
	}

	/**
	 * Adds a filetype "dot" extension to filter against.
	 * 
	 * For example: the following code will create a filter that filters out all
	 * files except those that end in ".jpg" and ".tif":
	 * 
	 * ExtensionFileFilter filter = new ExtensionFileFilter();
	 * filter.addExtension("jpg"); filter.addExtension("tif");
	 * 
	 * Note that the "." before the extension is not needed and will be ignored.
	 */
	public void addExtension(String extension)
	{
		if (filters == null)
		{
			filters = new Hashtable(5);
		}
		filters.put(extension.toLowerCase(), this);
		fullDescription = null;
	}

	/**
	 * Returns the human readable description of this filter. For example: "JPEG
	 * and GIF Image Files (*.jpg, *.gif)"
	 * 
	 * @see setDescription
	 * @see setExtensionListInDescription
	 * @see isExtensionListInDescription
	 * @see FileFilter#getDescription
	 */
	@Override
	public String getDescription()
	{
		if (fullDescription == null)
		{
			if (description == null || isExtensionListInDescription())
			{
				fullDescription = description == null ? "(" : description
						+ " (";
				// build the description from the extension list
				Enumeration extensions = filters.keys();
				if (extensions != null)
				{
					fullDescription += "." + (String) extensions.nextElement();
					while (extensions.hasMoreElements())
					{
						fullDescription += ", "
								+ (String) extensions.nextElement();
					}
				}
				fullDescription += ")";
			} else
			{
				fullDescription = description;
			}
		}
		return fullDescription;
	}

	/**
	 * Sets the human readable description of this filter. For example:
	 * filter.setDescription("Gif and JPG Images");
	 * 
	 * @see setDescription
	 * @see setExtensionListInDescription
	 * @see isExtensionListInDescription
	 */
	public void setDescription(String description)
	{
		this.description = description;
		fullDescription = null;
	}

	/**
	 * Determines whether the extension list (.jpg, .gif, etc) should show up in
	 * the human readable description.
	 * 
	 * Only relevent if a description was provided in the constructor or using
	 * setDescription();
	 * 
	 * @see getDescription
	 * @see setDescription
	 * @see isExtensionListInDescription
	 */
	public void setExtensionListInDescription(boolean b)
	{
		useExtensionsInDescription = b;
		fullDescription = null;
	}

	/**
	 * Returns whether the extension list (.jpg, .gif, etc) should show up in
	 * the human readable description.
	 * 
	 * Only relevent if a description was provided in the constructor or using
	 * setDescription();
	 * 
	 * @see getDescription
	 * @see setDescription
	 * @see setExtensionListInDescription
	 */
	public boolean isExtensionListInDescription()
	{
		return useExtensionsInDescription;
	}
}
